1. Field of the Invention
The present invention relates to an information processing apparatus that receives information via a network and executes a response process to the received information concerned, a control method therefor, and a storage medium storing a control program therefor.
2. Description of the Related Art
In recent years, information processing apparatuses that are provided with a power saving mode have spread. For example, Japanese Laid-Open Patent Publication (Kokai) No. 2009-151537 (JP 2009-151537A) discloses an information processing apparatus that has a main control unit and a sub control unit, reduces (or cuts) power supply to the main control unit in the power saving mode than in a normal mode, and executes a network response by the sub control unit without recovering the power supply to the main control unit to the normal mode.
Incidentally, the apparatus disclosed in JP 2009-151537A uses the sub control unit to respond to an incoming packet that can be responded by the sub control unit without operating the main control unit in the power saving mode.
On the other hand, when an incoming packet cannot be responded by the sub control unit, the apparatus recovers the power supply to the main control unit to the normal mode (a normal power mode), and then, the main control unit executes the network response.
Then, when the main control unit returns to the normal power mode, the sub control unit passes the incoming packet that is difficult to respond by the sub control unit to the main control unit. Accordingly, the main control unit can respond to the incoming packet shortly after returning to the normal power mode without waiting for resending of a packet by a packet transmitting source.
In this case, the sub control unit must stop from writing an incoming packet to a receive buffer until the return to the normal power mode is completed so that the incoming packet passed to the main control unit may not be overwritten by a following incoming packet. Therefore, network connection (link) is once disconnected and is reestablished when the return to the normal power mode is performed.
As a result, since the main control unit cannot perform the network communication at all until the link is reestablished even after returning to the normal power mode, a network response is delayed.